CLEANUP: fix a few typos in the comments of the server subsystem

A few misspells where detected in the server subsystem. This commit
fixes them.
diff --git a/include/types/server.h b/include/types/server.h
index a2e11c3..9586fb8 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -272,7 +272,7 @@
 	struct dns_resolvers *resolvers;	/* pointer to the resolvers structure used by this server */
 	char *lastaddr;				/* the address string provided by the server-state file */
 	struct dns_options dns_opts;
-	int hostname_dn_len;			/* sting lenght of the server hostname in Domain Name format */
+	int hostname_dn_len;			/* sting length of the server hostname in Domain Name format */
 	char *hostname_dn;			/* server hostname in Domain Name format */
 	char *hostname;				/* server hostname */
 	struct sockaddr_storage init_addr;	/* plain IP address specified on the init-addr line */
@@ -322,7 +322,7 @@
 		short status, code;
 		char reason[128];
 	} op_st_chg;				/* operational status change's reason */
-	char adm_st_chg_cause[48];		/* adminstrative status change's cause */
+	char adm_st_chg_cause[48];		/* administrative status change's cause */
 };
 
 /* Descriptor for a "server" keyword. The ->parse() function returns 0 in case of